<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        // a = 7;
        // console.log(a);

        var b;
        console.log(b);

        // document.querySelector


        var a = "1111";
        console.log('1'==1);//true
    </script>
    <script>
        console.log("a\"bc");
        console.log('a"bc');
        console.log("a'bc");

        var 你好 = 7
        console.log(你好);

        // int a = 8;
        // string s = '1'
        console.log(111);

        var o1 = {age:4}
        var o2 = {age:4}
        console.log(o1==o2);
    </script>
</body>
</html>